A natural analogue for high-level waste in tuff: Chemical analysis and modeling of the Valles site
- Sandia National Labs., Albuquerque, NM (United States)
- US Nuclear Regulatory Commission, Washington, DC (United States)
- Univ. of Alaska, Fairbanks, AK (United States)
The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a high-level waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock Tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, x-ray diffraction, and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 40}Ar isotopic composition. Overall, the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 m of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 37753
- Report Number(s):
- SAND-95-0271C; CONF-950216-76; ON: DE95008533; TRN: 95:009607
- Resource Relation:
- Conference: Waste management `95, Tucson, AZ (United States), 26 Feb - 2 Mar 1995; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
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